1. Field of the Invention
The aim of this invention is a header and removable pin arrangement, used particularly for fly screens.
The invention has particular, but not necessarily exclusive, application in the fixture accessories sector, such as fly screens, roller blinds and sun blinds.
2. Description of the Related Art
Fly screens are divided into two categories. The first type is made to measure, manufactured according to the dimensions required for a given client, delivered to the said client and installed by a specialised installation technician. The other type is sold in kit form, and is the type that is most widely available on the market.
The latter type of fly screen is reasonably efficient and economic and is the type at which this invention is mainly aimed. It is far more widespread on the market, and large quantities of components have to be fabricated and transported by the manufacturing companies, especially when dealing with overseas markets. The xe2x80x9cdo-it-yourselfxe2x80x9d concept is widely used and offers a product that satisfies most normal requirements, although it is not up to the standards of the made-to-measure type. Both of the examples mentioned have certain components in common, such as the casing, which is generally made from extruded aluminium bar. It is used to contain the rewind mechanism for the fly screen, roller blind or sun blind, and the manual version has a corresponding loaded return spring. The ends of the casing are sealed by special plates or headers, which are supplied in two different versions, a fixed type or together with counter-plates or caps that can be regulated.
There are obviously a number of variations, although they are very similar to the systems described, and are just as common in fly screens as in roller blinds and sun blinds. One of these variations is a lower quality fly screen without the aforementioned return spring inside its mechanism. They differ from the first type in that they are manually operated both for unwinding and rewinding the fly screen. In this case, a typical example uses a closed-loop chain that engages a cog fixed on the relative rewind roll contained inside a casing for unwinding and rewinding the fly screen, roller blind or sun blind in a controlled manner.
These solutions foresee the fabrication of structures, for example fly screens, which are made up as follows:
a casing;
a rewind roll contained inside the said casing with each end supported by a pair of headers, at least one of which runs freely on its relative support pin which is, in turn, joined firmly to the said header, and with the said headers joined to the ends of the casing;
a helicoidal torsion spring positioned co-axially to the said rewind roll, with one end fastened to a support means inside the roll that is free to slide longitudinally, and the other end firmly fastened to a support pin fastened to the header that forms the tensioning means;
a rod positioned co-axially to the said helicoidal spring, with one end inserted in the middle of the support means inside the roll that is free to slide longitudinally, and the other end embedded in the support pin fastened to the header that forms means for putting the spring in tension.
Each header, respectively the right one and the left one, is made up of a monolithic plastic body which has a bottom with a curved, protruding border around the perimeter that presses against the corresponding end of the profile of the casing.
The header usually has an off-centre flat part on the bottom side which, apart from being used to fix it to the wall, holds the upper ends of the guide runners along which the sides of the roller-blind slide.
A standard characteristic of both the right-hand and left-hand headers is that there is a protruding, monolithic, cylindrical pin on one side. The purpose of the pin, as mentioned above, is to support the rewind roll and rewind mechanism, if foreseen, which is made up of a helicoidal spring, a coaxial rod and a mobile support fixed to the rod inside the said rewind roll.
These solutions, regarding the use of headers with monolithic pins, have a number of drawbacks that can not be overlooked.
The first drawback regards the complex stock management procedures that are required, since it is necessary to organise the headers according to left and right-hand sides and according to the various colours of the casing. In this specific case, the production programme during the winter foresees the manufacture of a certain number of headers according to the various colours, of the casings. The headers are then assembled firstly to the rewind roll and then to the casing, until the final product is ready. There is a marked lack of flexibility with this type of manufacturing process, since a certain header colour may not be present in a given production cycle or there may be a surplus of another header colour, operations which require constant monitoring and, because of possible misunderstandings, may even lead to delays in their delivery. A further drawback is the costs involved in having to keep a large stock of materials constantly available for every header colour required, costs which, because of the production planning required, are very high and end up weighing heavily on the final product.
A second drawback regards the fact that at least two types of header have to be kept in stock, apart from the standard type for one of the ends of the casing, that is, a first type for the assemblies that have a rewind mechanism such as a traditional spring in tension, and a second type for those assemblies that have no rewind mechanism and are completely manually operated. This type of organisation is due to the fact that the first type of header is monolithic and has only the protruding pin to which the rewind roll is attached, while the second type is assembled together with a wheel or pulley arrangement for the rewind roll which is specially designed. for use with this type of header.
The third drawback regards the assembly phase of the casing. In the case of a fly-screen with a helicoidal rewind spring, the spring is put in tension by rotating the header in one direction before inserting the assembly in the casing. It is easy to imagine that this operation is quite complex and difficult, and requires quite a large amount of time and labour. In view of the drawbacks mentioned above, alternative solutions are obviously required and the aim of the invention described herein is to overcome the aforementioned drawbacks.
This and other aims are achieved through the use of this invention according to the characteristics in the attached claims, solving the problems described by means of a header to support one end of a rewind roll and to close off at least one end of the casing, used particularly for fly screens, and including:
a bottom from which, along the perimeter of the side close to the casing, there is a discontinuous border that protrudes, with a number of seats for fitting the corresponding end of the said header;
a flat, monolithic part formed in the said bottom that protrudes downwards, with holes formed on the surface in order to fasten it to the uprights of an opening;
wherein, in said bottom there is a central hole with a key-way into which the end of a pin is connected and thus fixed to the said part of the header. The end is mushroom shaped and is flexible, and fits into a hollow in the rear part, that is, on the side on the outside of the said header.
In this way, through the creative contribution of the system, which leads to an immediate technical progress, various advantages are achieved.
The first and, without a doubt, the most important advantage is that only a single type of header that is fastened to the corresponding end of the casing is required, and that it can be tinted as and when required. In fact, the said headers may be made from one single colour and, since no pre-assembly operation with the rewind roll is required, they are tinted only when a certain order has to be completed. This means that stock management is much simpler, and it is no longer necessary to have headers in various colours in stock, but only a single type.
What is more, all the rewind mechanisms, in this case pre-assembled helicoidal springs, will all be the same and the phase in which they are coupled with their respective headers will no longer be required, leading to a reduction in the space required and the amount of material transfer. In this way, stock management is much simpler, completion of orders is much quicker with relatively simple organisational procedures, and with orders being met on time.
A second advantage concerns the flexibility of this type of header, in that by connecting a pulley to it, it may also be used for the type of fly-screen that uses a closed-loop chain system together with the pulley for rotating the rewind roll, rather than the type that uses a spring-loaded rewind mechanism.
A further important advantage is that the end of the pin fastened to the header has a coaxial slot where a tool can be inserted in order to put the spring in tension by a simple rotary movement, rather than with previous versions where the entire header has to be rotated.
These and other advantages will be shown in the following detailed description and drawings of at least one preferred application of the system, which is to be considered merely an illustration and not a limitation.